Cytochrome P450 Complement May Contribute to Niche Adaptation in Serpula Wood-Decay Fungi.

Andrew Cowan,Inger Skrede,Suzy Clare Moody

doi:10.3390/jof8030283

Andrew Cowan, Inger Skrede + Show 1 more

Open Access

https://doi.org/10.3390/jof8030283

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Abstract

Serpula wood-decay fungi occupy a diverse range of natural and man-made ecological niches. Serpula himantioides is a forest-floor generalist with global coverage and strong antagonistic ability, while closely related species Serpula lacrymans contains specialist sister strains with widely differing ecologies. Serpula lacrymans var. shastensis is a forest-floor specialist in terms of resource preference and geographic coverage, while Serpula lacrymans var. lacrymans has successfully invaded the built environment and occupies a building-timber niche. To increase understanding of the cellular machinery required for niche adaptation, a detailed study of the P450 complement of these three strains was undertaken. Cytochrome P450 monooxygenases are present in all fungi and typically seen in high numbers in wood decay species, with putative roles in breakdown of plant extractives and lignocellulose metabolism. Investigating the genomes of these related yet ecologically diverse fungi revealed a high level of concordance in P450 complement, but with key differences in P450 family representation and expression during growth on wood, suggesting P450 proteins may play a role in niche adaptation. Gene expansion of certain key P450 families was noted, further supporting an important role for these proteins during wood decay. The generalist species S. himantioides was found to have the most P450 genes with the greatest family diversity and the highest number of P450 protein families expressed during wood decay.

Highlights

Cytochrome P450 monooxygenases (P450s) are ubiquitous in eukaryotic organisms the number and composition of the P450 complement varies widely between species, genera and ecological niches [1,2])
Serpula himantioides (SH) had predicted proteins tentatively assigned to 41 different families and 11 proteins which met the strict inclusion criteria but did not have a match greater than 40% with any known P450 protein, which were designated ‘novel’ (Figure 1a)
SH occupies a generalist forest floor niche where it is able to utilise a range of softwoods [28], while S. lacrymans has evolved to occupy more specialist environments

Summary

Introduction

Cytochrome P450 monooxygenases (P450s) are ubiquitous in eukaryotic organisms the number and composition of the P450 complement varies widely between species, genera and ecological niches [1,2]). Studies of fungal P450 complement identified Ascomycete saprotrophs Aspergillus nidulans and Neurospora crassa as having 109 and 41 P450 genes, respectively [3], A. nidulans was later suggested to contain 111 P450 genes, [4], while the genome of the model wood decay Basidiomycete Phanerochaete chrysosporium was found to contain 148 P450 sequences [5]. Most cytochrome P450s are thought to be adaptive, fulfilling roles that enable the organism to survive in a particular niche or specific environmental conditions. A subset of P450 families is represented exclusively in the genomes of fungal wood decay species, and it has been proposed that members of this subset are important for detoxification of plant breakdown products and extractives, potentially increasing the range of nutritional resources available to the fungus [9]

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